Why Running Keeps Your Brain Healthy as You Age

New research indicates that people who run more than 15.3 miles per week earlier in life have a 40 percent lower risk of Alzheimer’s disease mortality.

The study, which appeared in a prepublication from the Journal of Alzheimer’s Disease, also found that eating at least three pieces of fruit per day and taking statins to lower cholesterol could also lower the risk of Alzheimer’s disease mortality by approximately 60 percent.

“Currently, doctors do not screen for Alzheimer’s disease susceptibility because of the belief that nothing can be done for those at risk,” said the study’s author, Dr. Paul Williams. "However, our results add to the growing body of scientific evidence suggesting that people can be proactive in lowering Alzheimer’s disease risk.”

The research was based on data from the National Runners’ Health Study and the National Walkers’ Health Study. Participants provided information about their exercise habits, diet, and disease history, among other things, via a questionnaire.

The study examined the habits of more than 154,000 runners and walkers during an 11+ year period. Among that group, there were 175 deaths in which Alzheimer’s was diagnosed as an underlying or contributing cause.

While runners who ran 15.3 miles per week had a 40 percent lower risk for Alzheimer’s disease mortality, those who ran 4.6 to 7.7 miles per week did not lower their risk. Compared to the group who ran more than 15.3 miles per week, those who expended an equivalent amount of energy walking had similar risk reductions.

Dr. Williams noted, however, that “One must walk about 50 percent [farther], and take about twice as much time walking briskly to expend the same amount of energy as running a 12-minute mile.”

So why does moving keep your noggin in check as you age? Dr. Williams suggests that areas of the brain like the hippocampus—vital for short- and long-term memory—have larger amounts of gray matter volume in older adults when they are more physically active in their lives. Other studies have also shown that when older adults continue exercising they have greater brain connectivity function as shown in attention and memory tests.